How do coral reefs have an affect on people?

Coral reefs are here in our world, and we have a duty to protect them. Things like fertilizers and pesticides are the things that are harming them, which comes from humans and causes the reefs to get sick. 

If that answer isn't enough, then maybe this one will help?
Over fishing occurs when humans fish more than they should in a coral reef and eventually the fish can no longer thrive, and they simply disappear. Not only is this bad for the reef, because it too will then die, but them humans will no longer have that source of fish, which is what man groups of people and fisher man need to keep their businesses running and is where people get a main source of food. Fishing is what keeps many people alive and keeps smaller fishing villages running, and without it, they cannot survive either.